The present disclosure relates generally to document image processing, computer vision and video analysis.
Computing devices (e.g., smartphones, mobile phones, laptops, tablet computers, notebooks, personal digital assistants, etc.) are becoming increasingly available worldwide. Moreover, computing devices are becoming more portable and more powerful. These devices are always at hand and their capabilities are comparable with those of a personal computer (PC). Computing devices have become indispensable assistants in business, education, communication, in travel and in everyday life, especially for capturing images, because almost all of these devices include a camera built into them. Various software applications, available for installation on the computing device, may provide methods and means of processing captured images or recorded video received from a mobile camera. Some of these applications may include features related to optical or intelligent character recognition (OCR or ICR) exist.
During the process of character recognition, a common situation arises when the input image does not have enough resolution for the text to be easily recognized. Low resolution source images may be caused by various reasons such as: limited resolution of the camera matrix built into the electronic device, lack in the optical system of an electronic device, data encryption algorithms, insensitive or crude compression algorithms. The imperfections in the use of a mobile camera such as hands shakes and non-ideal light conditions may cause defects in the captured images. Optical distortion and motion blur can be caused by limited shutter speed. Noise, aliasing effects, defocusing, and glares can negatively impact image quality. These shortcomings often interfere with subsequent processing of the images.